import com.google.common.collect.Iterables;
-import java.io.FileNotFoundException;
import java.io.IOException;
import java.time.Duration;
import java.util.Properties;
import org.springframework.stereotype.Component;
/**
- * The class fetched incoming requests from DMAAP on regular intervals. Each
- * received request is proceesed by DmaapMessageHandler.
+ * The class fetches incoming requests from DMAAP. It uses the timeout parameter
+ * that lets the MessageRouter keep the connection with the Kafka open until
+ * requests are sent in.
+ *
+ * <p>
+ * this service will regularly check the configuration and start polling DMaaP
+ * if the configuration is added. If the DMaaP configuration is removed, then
+ * the service will stop polling and resume checking for configuration.
+ *
+ * <p>
+ * Each received request is processed by {@link DmaapMessageHandler}.
*/
@Component
-public class DmaapMessageConsumer implements Runnable {
+public class DmaapMessageConsumer {
- private static final Logger logger = LoggerFactory.getLogger(DmaapMessageConsumer.class);
+ protected static final Duration TIME_BETWEEN_DMAAP_RETRIES = Duration.ofSeconds(10);
- private final static Duration TIME_BETWEEN_DMAAP_POLLS = Duration.ofSeconds(10);
+ private static final Logger logger = LoggerFactory.getLogger(DmaapMessageConsumer.class);
private final ApplicationConfig applicationConfig;
- @Value("${server.port}")
- private int localServerPort;
+ private DmaapMessageHandler dmaapMessageHandler = null;
+ private MRConsumer messageRouterConsumer = null;
+
+ @Value("${server.http-port}")
+ private int localServerHttpPort;
@Autowired
public DmaapMessageConsumer(ApplicationConfig applicationConfig) {
this.applicationConfig = applicationConfig;
-
- Thread thread = new Thread(this);
- thread.start();
}
- DmaapMessageConsumer(ApplicationConfig applicationConfig, boolean start) {
- this.applicationConfig = applicationConfig;
- }
-
- private boolean isDmaapConfigured() {
- Properties consumerCfg = applicationConfig.getDmaapConsumerConfig();
- Properties producerCfg = applicationConfig.getDmaapPublisherConfig();
- return (consumerCfg != null && consumerCfg.size() > 0 && producerCfg != null && producerCfg.size() > 0);
+ /**
+ * Starts the consumer. If there is a DMaaP configuration, it will start polling
+ * for messages. Otherwise it will check regularly for the configuration.
+ *
+ * @return the running thread, for test purposes.
+ */
+ public Thread start() {
+ Thread thread = new Thread(this::messageHandlingLoop);
+ thread.start();
+ return thread;
}
- @Override
- public void run() {
- while (sleep(TIME_BETWEEN_DMAAP_POLLS) && isDmaapConfigured()) {
+ private void messageHandlingLoop() {
+ while (!isStopped()) {
try {
- Iterable<String> dmaapMsgs = fetchAllMessages();
- if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
- logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
- for (String msg : dmaapMsgs) {
- processMsg(msg);
+ if (isDmaapConfigured()) {
+ Iterable<String> dmaapMsgs = fetchAllMessages();
+ if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
+ logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
+ for (String msg : dmaapMsgs) {
+ processMsg(msg);
+ }
}
+ } else {
+ sleep(TIME_BETWEEN_DMAAP_RETRIES); // wait for configuration
}
} catch (Exception e) {
- logger.warn("{}: cannot fetch because of {}", this, e.getMessage());
- sleep(TIME_BETWEEN_DMAAP_POLLS);
+ logger.warn("Cannot fetch because of {}", e.getMessage());
+ sleep(TIME_BETWEEN_DMAAP_RETRIES);
}
}
}
- private Iterable<String> fetchAllMessages() throws ServiceException, IOException {
+ protected boolean isStopped() {
+ return false;
+ }
+
+ protected boolean isDmaapConfigured() {
+ Properties consumerCfg = applicationConfig.getDmaapConsumerConfig();
+ Properties producerCfg = applicationConfig.getDmaapPublisherConfig();
+ return (consumerCfg != null && consumerCfg.size() > 0 && producerCfg != null && producerCfg.size() > 0);
+ }
+
+ protected Iterable<String> fetchAllMessages() throws ServiceException, IOException {
Properties dmaapConsumerProperties = this.applicationConfig.getDmaapConsumerConfig();
MRConsumer consumer = getMessageRouterConsumer(dmaapConsumerProperties);
MRConsumerResponse response = consumer.fetchWithReturnConsumerResponse();
getDmaapMessageHandler().handleDmaapMsg(msg);
}
- private DmaapMessageHandler getDmaapMessageHandler() throws IOException {
- String agentBaseUrl = "http://localhost:" + this.localServerPort;
- AsyncRestClient agentClient = createRestClient(agentBaseUrl);
- Properties dmaapPublisherProperties = applicationConfig.getDmaapPublisherConfig();
- MRBatchingPublisher producer = getMessageRouterPublisher(dmaapPublisherProperties);
-
- return createDmaapMessageHandler(agentClient, producer);
+ protected DmaapMessageHandler getDmaapMessageHandler() throws IOException {
+ if (this.dmaapMessageHandler == null) {
+ String agentBaseUrl = "http://localhost:" + this.localServerHttpPort;
+ AsyncRestClient agentClient = new AsyncRestClient(agentBaseUrl);
+ Properties dmaapPublisherProperties = applicationConfig.getDmaapPublisherConfig();
+ MRBatchingPublisher producer = MRClientFactory.createBatchingPublisher(dmaapPublisherProperties);
+ this.dmaapMessageHandler = new DmaapMessageHandler(producer, agentClient);
+ }
+ return this.dmaapMessageHandler;
}
- boolean sleep(Duration duration) {
+ protected void sleep(Duration duration) {
try {
Thread.sleep(duration.toMillis());
- return true;
} catch (Exception e) {
logger.error("Failed to put the thread to sleep", e);
- return false;
}
}
- MRConsumer getMessageRouterConsumer(Properties dmaapConsumerProperties) throws FileNotFoundException, IOException {
- return MRClientFactory.createConsumer(dmaapConsumerProperties);
- }
-
- DmaapMessageHandler createDmaapMessageHandler(AsyncRestClient agentClient, MRBatchingPublisher producer) {
- return new DmaapMessageHandler(producer, agentClient);
- }
-
- AsyncRestClient createRestClient(String agentBaseUrl) {
- return new AsyncRestClient(agentBaseUrl);
+ protected MRConsumer getMessageRouterConsumer(Properties dmaapConsumerProperties) throws IOException {
+ if (this.messageRouterConsumer == null) {
+ this.messageRouterConsumer = MRClientFactory.createConsumer(dmaapConsumerProperties);
+ }
+ return this.messageRouterConsumer;
}
- MRBatchingPublisher getMessageRouterPublisher(Properties dmaapPublisherProperties)
- throws FileNotFoundException, IOException {
- return MRClientFactory.createBatchingPublisher(dmaapPublisherProperties);
- }
}